Signaling apparatus



July 24, 1934. E. GRETENER SIGNALING APPARATUS Filed April 21, 1932 Patented July 24, 1 934 c 1,967,404 SIGNALING APPARATUS 1 Edgar Gretener; Berlin, Germany, assignor to Siemens & Halske Aktiengesellschaft, Wernerwerk Siemensstadt, near Berlin, Germany Application April 21, 1932, Serial No. 606,73

In Germany April 22, 1931 12 Claims.

, This invention relates to the use of neon lamps operating as signal indicators or receiving relays for signal transmission in communication systems and preferably in telephone systems.

According to one feature .of the invention, the neon lamps are disposed in circuits coupled inductively to thelines; ,-The lamp circuits are normally energized by a potential whichis kept between the striking and the extinguishing voltage of the lamps; Signaling current applied to a line is superimposed on'the circuitof theassociated lamp, causing the" lamp to strike. The lamp then remains lightedby the potential normally applied to its circuit until the current is interrupted upon thezcall being answered. A very simple and inexpensive line signaling arrangement isthus provided. i l

An additional feature of the invention relates to a method of supplyingfthe neon lamps with an extra impedance so as to reduce their sensitiveness to voltage peaks occurring during a conversation. By means of this ararngement, the mean speech level .also may be dropped according to the voltage of the neon lamps. 1

Thefeatures of the invention are more fully explained in conjunction with the accompanying drawing, comprising Figs. 1 and 2'. Fig.1 shows the embodiment of the invention in a system em ploying double ended cord circuits; Fig. 2 shows the embodiment of the invention in a system employing single ended cordcircuits.

- Referring nowtoFigsl, three have been shown. A series of additional lines may beconnected upin a similar manner. ,,The lines are associated with corresponding; neon lamps G1, G2, G3, their. circuitshaving a common portion formed by the current source of supply E1, fromwhich the pre-applied potential is derived, and the relay, R; Parallel with the current source of supply and relay R is connected the condenser Kl which serves the purpose of preventing a plurality of neon lamps from lightings'imultaneously in consequence of the common coupling unit R. A connection between two lines, for example the lines L1 and L3, is made in the following manner: a

The neon lamp G1 lights up when the subscriber associated with line L1 initiates a call by ringing over the line. The exchange operator inserts the plug designated a, b, c of the connecting cord S into the corresponding jack of the line L1 and throws the change-over key U into the position in which enquiries'are made, i. e. to

the right. Inserting the plug as mentioned causes Zthe primarywinding of the repeater T1 to be dislines L1, L2, L3

connected from the line L1, and the contact spring 0 is thrown from d over to e. This extinguishes the neon lamp G1, and the following circuit for the neon lamp G4, provided to indicate the clear ing signal, is prepared: positive pole ofbattery E1, primary winding of the repeaterT l, C14, e, 0, negative pole of battery E1. The contacts Z, m and n are closed when the switch key U is set in enquiry position. Consequently the transmitter circuit for the operators speaking set is closed over E3, M, Z; primary Winding T5. The secondary circuit of the repeater T5 is connectedto the'line L1 over a circuit extending from secondary winding T5, receiver H, m, a, a, L1, b,b, n secondary winding T5. The L1 line subscribers request for a connection with the line L3 is duly noted and the plug a, b",'c", of the. connecting cord S is in-. serted into the jack which corresponds to the required line L3. The repeater T3 and the neon lamp G3 are then disconnected from the line L3, and a second circuit for the clearing signal lamp G4 is prepared over the jack spring 0 and contact e. Ringing current is then transmitted to the subscriber connected to line L3 by the switch key U being turned over to the left; Contacts g, h are opened and contacts 1, 11 and k are closed. The pole alternator P, which acts as a ringing current source of supply, is'caused to operate over: battery E2, 7c, interrupter contact and magnet winding of said pole alternator. Positive and negative impulses are alternately transmitted through the primary winding of the repeater T6 over contacts 0 and p with the result that corresponding impulses pass tothe line L3 over contacts f and i and the plug leads a and b" and cause the subscribers ringer to operate. The condenser K3 may serve to smooth the ringing impulses. i 1 1 r The switch key U is now restored to speaking position,,that is-to say, it is thrown into its c'entral position, and the connection between the two subscribers is then completed. The. condenser K2 which is connectedin parallel withthe neon lamp G4 prevents said neon lamp from lighting up during the conversation due to voltage peaks. When at the end of the call one of the subscribers gives the clearing signal, the neon lamp G4 is lighted due to the fact that the condenser K2 is not operative with low frequency ringing current. Withdrawing the plugs a, b, c and a", b", 5 c" from the jacks causes the circuit over the neon lamp G4 to be cut oif at contacts c.

Fig. 2 shows a somewhat different arrangement in which each subscribers line is permanently connected to a cord' such as a, b, c.

The switching units corresponding to Fig. 1 are provided with the same reference characters. The neon lamp G1 is lighted when the subscriber associated with line Ll puts through a call. A momentary depression of the key S1 causes this lamp to be extinguished and the connection with the required line, for example the line L2, is set up. The plug leads a, b, c are connected to the corresponding jack springs or, b, c of line L2, thus causing the repeater T2 to be disconnected from line L2. The neon lamp G1 remains connected to line L1, over the repeater T1 since it is adapted to operate as a clearing signal. as Well. The condenser K3, which is connected to the plug lead 0 and to the jack spring 0 of line L2, and consequently also to the left hand side of the neon lamp G1 over the jack springs or of the lines L2 and L1,

so that it, therefore, is connected in parallel with said lamp, prevents the neon lamp from lighting up in consequency of voltage peaks occurring during the conversation. The neon lamp G1 is re lighted at the end of the call and therefore acts as a clearing signal.

What is claimed is:

1. In a telephone system, a line terminating in a primary winding of a repeating coil, a neon tube, a local circuit for said tube including the secondary winding of the repeating coil and a source of current whose potential is between the striking and extinguishing voltages of the tube, and manually controlled means for opening said local circuit.

2. In a telephone system, a line, a repeating coil having its primary winding bridged across the line,

= a neon tube associated with the line as a calling signal, a local circuit for said tube including the secondary winding of the repeating coil and a source of current whose potential is between the striking voltage and releasing voltage of the tube,

' means for extending a connection to the line, and

contacts controlled by said last means for disconnecting the repeating coil from the line and for opening said local circuit.

3. In a telephone system, a plurality of lines each terminating in the primary winding of a repeating coil, a neon tube associated with each of said lines as a calling signal, a common circuit including a source of current, a relay and a con denser, and a local circuit for each of said tubes, each circuit including the secondary winding of the associated repeating coil and said common circuit.

4. In a telephone system, a line, a neon tube associated with 'theline at the exchange, circuit connections for causing said tube to strike responsive to a call signal on the line and to remain lighted, and manually controlled means for momentarily opening said circuit connections to extinguish the tube whereby the same is prepared to strike in response to a disconnect signal.

5. In a telephone system, a line, a neon tube associated with the line, circuit connections for causing the tube to light responsive to a call signal on the line, means for answering the call and for extending the same to the called line, and means responsive to the extension of the call for connecting a condenser in parallel with said tube.

6. A telephone system as claimed in claim 4 in which current of a potential insufficient to cause the tube to strike but suflicient to prevent it from extinguishing is normally applied to the tube independent of the line.

'7 In a telephone system, a plurality of lines each terminating in the primary winding of a repeating coil, a common source of current, a neontube associated with each line, a local circuit for each tube including the secondary winding the associated repeating coil and said common current source, means responsive to a call on a line for lighting the associated tube, a cord circuit adapted to connect with the lines to answer calls thereon, a neon tube adapted to operate as a disconnect signal for any'of said lines, and means responsive to the connection of the cord circuit to a calling line for opening the local circuit of the tube associated with the line, for completing a local circuit including said common current source for said other neon tube, and for inductively connecting said last mentioned local circuit with the line.

8. A telephone system as claimed in claim 7 in which the neon tube used for the disconnect signal is shunted by a condenser to render it less sensitive to current peaks set up during conversations.

9'. In a telephone system, subscribers lines, means including a cord circuit at the exchange for connecting two of said lines forconversation, a neon lamp associated with said cord circuit as a supervisory signal, and circuit connections for said lamp such that a ring off signal received at said cord circuit will cause the lamp to operate.

10. In a telephone system as set forth in claim 9, means for extinguishing the lamp when the connection is pulled down.

11. In a telephone system, a plurality of subscribers lines, means at the exchange for connecting two of said lines in a talking circuit, a neon lamp at the exchange functioning as a disconnect signal, a source of current applied to said lamp tomaintain the same operated after its operation has'been initiated, and circuit connections between the talking circuit and said lamp such that ringing current transmitted over one of the connected lines will initiate the operation of said lamp.

12. In a telephone system, subscribers lines, means for answering a call on one of said lines and for connecting the same with another of said lines, a neon lamp, and circuit connections for said lamp such that the same operates as a call signal to call the operator and as a supervisory signal after the connection is completed.

. GRETENER, EDGAR.

III. 

